Oxygen respirator Q&A on site, so comprehensive!

Friends often ask the following questions after receiving the oxygen respirator:

I. Why doesn't the oxygen respirator come with an instruction manual?

Each oxygen respirator is equipped with an instruction manual and a certificate of conformity. The serial number on the certificate matches the printed code on the oxygen respirator, making the certificate unique.

Also, the instruction manual and the certificate of conformity are not directly placed in the cardboard box packaging, but rather in the aluminum case packaging. You need to open the aluminum case to see them.